1. Field of the Invention
The present invention relates to a projector device adapted to guide light from a light source to an optical system to generate image light for magnification projection on a forward screen.
2. Description of Related Art
Conventionally known as a projector device of this type is a liquid crystal projector device adapted to separate white light emitted from a light source into three primary colors of blue, green, and red for incidence on three liquid crystal panels for three primary colors, to synthesize the light transmitted by the liquid crystal panels with a color synthesis prism to generate a color image, and to magnifyingly project the color image on a forward screen with a projection lens.
Known as one of those as described above is a liquid crystal projector device having optical compensation sheets arranged at light incidence sides or light emergence sides of the respective liquid crystal panels for the respective colors in order to prevent light leak. The optical compensation sheets have liquid crystal molecules therein. The optical compensation sheets are attached such that the liquid crystal molecules have a slow axis in a direction parallel to an alignment direction of liquid crystal molecules constituting the respective liquid crystal panels to thereby perform a function of blocking incidence of unwanted component waves of light on the respective liquid crystal panels. This can prevent light leak and uneven coloring from occurring in the liquid crystal panels.
The optical compensation sheets are prepared by being cut in a necessary size from a sheet material. Therefore, the optical compensation sheets have variations within a certain tolerance in the slow axis direction of the liquid crystal molecules in each of the optical compensation sheets. Therefore, an adjustment mechanism for adjusting the optical compensation sheets in place relative to the liquid crystal panels is necessary in order to attach the optical compensation sheets such that the liquid crystal molecules in the optical compensation sheets have a slow axis in a direction parallel to an alignment direction of liquid crystal molecules in the liquid crystal panels.
The applicant has proposed an optical compensation sheet holder constructed such that an optical compensation sheet is inclination-adjustable relative to an optical axis of a liquid crystal panel, and is rotation-adjustable within a plane perpendicular to the optical axis (JP 2006-039087, A). As shown in FIG. 48 and FIG. 49, the optical compensation sheet holder 200 includes a generally L-shaped turning member 210 for holding the optical compensation sheet 290, and an auxiliary member 220 to which the turning member 210 is fastened, and which is to be attached to a stationary part 251 erected on a chassis 250 of an optical system.
As shown in FIG. 49, the turning member 210 has a centrally provided opening 211, which allows light passage. The optical compensation sheet 290 is fitted in the opening 211. The upper part of the turning member 210 has a pair of first long holes 212, 212 longer along the optical axis L and provided at opposite sides across the optical axis L, and operation parts protruded from opposite ends thereof and to be operated by an adjustment worker.
The auxiliary member 220 has screw holes 221, 221, which are provided in positions corresponding to the pair of first long holes 212, 212, and into which screws 230, 230 for fastening the turning member 210 are screwed, a pair of second long holes 223, 223 longer in the direction perpendicular to the optical axis L and provided at opposite sides across the optical axis L, and a third long hole 222 longer in the direction perpendicular to the optical axis L.
The upper surface of the stationary part 251 on the chassis 250 has guide pins 252, 252 projectingly provided in positions corresponding to the pair of second long holes 223, 223 to penetrate through both long holes 223, 223, and a screw hole 253, which is provided in a position corresponding to the third long hole 222, and into which a screw 260 for fastening the auxiliary member 220 is screwed.
As described above, the optical compensation sheet holder 200 allows a first adjustment operation of sliding the optical compensation sheet holder 200, with the screw 260 loosened, in the direction perpendicular to the optical axis L, and a second adjustment operation of turning the turning member 210, with one of the two screws 230, 230 loosened, on the other screw to incline a surface of the optical compensation sheet 290 relative to a plane perpendicular to the optical axis L. Therefore, using the first and second adjustment operations, the above optical compensation sheet holder 200 enables the optical compensation sheet 290 to be adjusted in place such that liquid crystal molecules in the optical compensation sheet 290 have a slow axis in a direction parallel to an alignment direction of liquid crystal molecules in the liquid crystal panel.
However, the above optical compensation sheet holder 200 has caused a problem of poor workability because in the second adjustment operation the optical compensation sheet 290 turns with one of the two screws 230, 230 loosened on the other screw, and therefore the reference position of the turning axis of the optical compensation sheet 290 in adjustment work varies depending on where the other screw is screwed. In addition, the second adjustment operation could produce warpages and flexures in the auxiliary member 220, which produce a stress in the optical compensation sheet 290 attached to the auxiliary member 220. This has resulted in a problem of deviation of the slow axis direction of the liquid crystal molecules in the optical compensation sheet 290.